# Middleware

There are several middlewares available provided by Starlette directly.

Read more about them in the [FastAPI docs for Middleware](https://fastapi.tiangolo.com/advanced/middleware/).

::: fastapi.middleware.cors.CORSMiddleware

It can be imported from `fastapi`:

```python
from fastapi.middleware.cors import CORSMiddleware
```

::: fastapi.middleware.gzip.GZipMiddleware

It can be imported from `fastapi`:

# Sub-dependencies { #sub-dependencies }

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

    without stabilizing these new APIs first.

    Do not use these experimental APIs in modules that may be executed using a version of OkHttp
    different from the version that the module was compiled with. Do not use them in published
    libraries. Do not use them if you aren't willing to track changes to them.

 *  Breaking: Drop support for Kotlin Multiplatform.

    // Verify that these are the same escaper (as documented)
    assertSame(e, urlFormParameterEscaper());
    assertBasicUrlEscaper(e);

    /*
     * Specified as safe by RFC 2396 but not by java.net.URLEncoder. These tests will start failing
     * when the escaper is made compliant with RFC 2396, but that's a good thing (just change them
     * to assertUnescaped).
     */

// format. However, the GNU tar utility itself outputs these values in decimal.
// As such, this library treats values as being encoded in decimal.
func readGNUSparseMap1x0(r io.Reader) (sparseDatas, error) {
	var (
		cntNewline int64
		buf        bytes.Buffer
		blk        block
	)

	// feedTokens copies data in blocks from r into buf until there are

   *
   * <p>Whenever possible, it is preferable to test directly for some observable change resulting
   * from GC, as with {@link #awaitClear}. Because there are no guarantees for the order of GC
   * finalization processing, there may still be some unfinished work for the GC to do after this
   * method returns.
   *
   * <p>This method does not create any memory pressure as would be required to cause soft

want it, that you can change the software or use pieces of it in new
free programs; and that you know you can do these things.

To protect your rights, we need to make restrictions that forbid anyone
to deny you these rights or to ask you to surrender the rights. These
restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.

discretion.

In your report please include:

 * Your contact information.
 * Names (real, nicknames, or pseudonyms) of any individuals involved. If there are additional
   witnesses, please include them as well.
 * Your account of what occurred, and if you believe the incident is ongoing. If there is a publicly
   available record (e.g. a mailing list archive or a public IRC logger), please include a link.
 * Any additional information that may be helpful.

OkHttp HPACK tests
==================

These tests use the [hpack-test-case][1] project to validate OkHttp's HPACK
implementation.  The HPACK test cases are in a separate git submodule, so to
initialize them, you must run:

    git submodule init
    git submodule update

TODO
----

 * Add maven goal to avoid manual call to git submodule init.
 * Make hpack-test-case update itself from git, and run new tests.

Here's the reference information for the request parameters.

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python